Press and wire for incandescent lamps, radio tubes, and the like



ratemeu June 60, 130! UNITED STATES PATENT OFFICE .PRESS AND WIRE FORINCANDESCENT LAMPS, RADIO TUBES, AND THE LIKE No Drawing. ApplicationMarch 6, 1931, Serial No. 520,721

3 Claims.

This invention relates to an improved copper wire for use as the lead inwires to be welded to the wires passing through the glass seal inincandescent lamps, radio lamps or tubes, and like devices, and has foran object to provide an improved copper wire which will more readily andeffectively operate for the automatic electric welding of these lead inwires to the wires passing through the glass seal, and will give abetter and stronger connection which will not become brittle insubsequent manufacturing operations for the lamp, tube or the like.

It is a more specific object of the invention to provide a specialmanganese deoxidized copper wire which will contain suflicient manganeseto secure the above noted results.

With the foregoing and other objects in view the invention consists incertain novel features as will be more fully disclosed and pointed outhereinafter.

In all lamps of the above description (the term lamp being used toinclude radio tubes and similar devices as well as incandescent lamps)the lead in wires are of copper, and practically the uni- 95 versalpractice in manufacturing is to automatically electrically weld theselead in wires to the metal wires that pass through the glass seal in thelamp or tube. It has heretofore been common practice to use standardelectrolytic copper wire for these lead in wires. This wire welds quitesatisfactorily but it contains a certain amount of oxygen in the form ofcuprous oxide distributed throughout the copper. This oxygen content maybe 0.10 percent or less. In certain operations in manufacturing some ofthe lamps it is necessary to heat the copper lead in wires in anatmosphere of hydrogen or other reducing gases, and during theseoperations these reducing gases react with the oxygen in theelectrolytic copper wire and reduce the cuprous oxide, or in other wordsthe 0 copper is gassed as this action is termed by the trade. This isvery objectionable because electrolytic copper that has been heated inhydrogen or other reducing atmospheres and becomes gassed is verybrittle and has very little strength, and therefore is practicallyworthless after this annealing in reducing atmospheres. In an attempt toovercome these objections I have found that wires prepared from certaindeoxidized copper behave very satisfactorily in the automatic electricwelding and in the subsequent annealing in hydrogen and other reducinggases.

In producing deoxidized copper wire the copper is first melted in acrucible or suitable furnace and after it is thoroughly melted adeoxidizer is added. Various deoxidizers such as phosphorous, silicon,aluminum and other deoxidizers well known to the art have been used. Thedeoxidizer combines with the oxygen in the molten copper and thus freesthe copper of oxygen as the oxygen combines with the deoxidizer andslags off leaving the copper free from oxygen. The metal is then pouredinto bars suitable for rolling, drawing etc. into wire.

On experimentation, however, it was found that copper deoxidized withvarious deoxidizers such for example, as phosphorus, silicon and othersmade very unsatisfactory welds, particularly when used in the automaticwelding machine for welding lead in wires to the wires leading throughthe glass seal in electric lamps, tubes and the like. I discovered,however, that manganese deoxidized copper wire in which a certain amountof manganese remained in the wire was very satisfactory both from thestandpoint of manipulation in the welding operation and the strength ofthe finished weld as well as standing up under subsequent manufacturingoperations for the lamps, and as having the required high electricconductivity.

In producing this wire the melting, pouring so and casting of thedeoxidized copper is so conducted that not only is the copper deoxidizedbut some manganese is retained in the copper. My experiments at thepresent time indicate that the preferred amount of manganese is fromabout 0.01 percent to about 0.10 percent, and that for best resultsabout 0.075 percent of manganese should remain in the copper. Smalleramounts of manganese will give fairly satisfactory results under certainconditions as will also somewhat greater amounts, but I have found thatabout these percentages of manganese retained in the deoxidized copperwire will give the most satisfactory results. If the manganese contentis much higher than 0.075 percent the electrical conductivity of thewire is lowered beyond the point which is satisfactory, as highelectrical conductivity is very desirable in lead in wires to lamps inorder to keep the resistance as low as possible. If a consumer iswilling to use a wire having a lower conductivity, a higher manganesecontent may be used.

With the manganese content lower than 0.075 percent there is greaterdanger of the wire not being properly deoxidized and also greater dangerof its not behaving properly in the automatic welding machine, but testsindicate that a manganese content in the deoxidized copper wire as lowas 0.001 percent, and as high as 0.25 percent would be fairlysatisfactory the higher content being capable of use where a lowerelectrical conductivity would be satisfactory. For best all roundresults about 0.075 percent manganese in the deoxidized copper wireappears to be the most satisfactory, although this manganese content maybe varied depending upon conductivity requirements. This assures thatthe copper is properly deoxidized so that We will not have the action ofgassing with its objectionable effects in subsequent manufacturingoperations.

The presence of the manganese prevents the absorption of oxygen duringthe welding operation, and also makes the metal weld more readily. Ithas further been found that this manganese deoxidized copper wirecontaining substantially the amounts of manganese mentioned behaves in apeculiar manner in the Welding operation, in that the bead of meltedmetal formed at the weld remains concentric with the Wire, whereas inwelding other types of deoxidized copper wire the bead is formedeccentrically in this class of work. This is very important as giving a.better and more reliable weld, particularly as these automatic weldingmachines operate with the wires in a horizontal position.

Having thus set forth the nature of my invention, what I claim is:

1. In combination a. press for incandescent lamps, radio tubes and thelike, a wire sealed in said press with one end adjacent thereto, and alead-in wire composed of copper containing manganese in amount from0.001 percent to approximately 0.25 percent welded to said adjacent end.

2. In combination a press for incandescent lamps, radio tubes and thelike, a wire sealed in said press with one end adjacent thereto, and alead-in wire composed of copper containing manganese in amount fromapproximately 0.010 percent to 0.10 percent welded to said adjacent end.

3. In combination a press for incandescent lamps, radio tubes and thelike, a Wire sealed in said press with one end adjacent thereto, and alead-in wire composed of copper containing approximately 0.075 percentmanganese welded to said adjacent end.

HERBERT C. JENNISON.

